Append/modify meta-data if metablock is present

[Procyon-b]

I've created a style on USO just to play with metaheaders. ´@updateURL` in particular. Ultimately I want to redirect my style(s) to a sites that handle install and update stats. userstyles.world seems to do this (haven't tried yet).

Apparently USO keeps the metablock unchanged at the top of the style, and USOa gets it and keeps it. The only problem is that USOa's adds its own userstyle meta-block (the update process somehow still partially works in stylus).

Could it be possible to check the presence of the block and only add some headers if necessary? The @version header could be valid as well as @updateURL (but that one must be checked to prevent a loop).

Here is the test style:

https://uso.kkx.one/style/207643
and the original on USO: https://userstyles.org/styles/207643/dummy-usercss-2